Fixed price, low bill
I think people want a low bill, at the advertised price, that never changes.
Let's take AT&T for example. They could offer a $50 plan, and provide what they can to still make a profit. Change the voice minutes, text messages, data cap, data speed, to whatever makes sense. But don't stick all these fees or increases on there.
Then Verizon could offer their own $50 plan, and compete on features. Leave out price as an issue, and see who has the better features.
Never happen, but a cell phone customer can dream